How have advances in comparative floral development influenced our understanding of floral evolution?

Evolutionary developmental biology has come to prominence in the past two decades, in both the plant kingdom and the animal kingdom, particularly following the description of homeotic genes linked to key morphological transitions. A primary goal of evolutionary developmental biology (“evo-devo”) is to define how developmental programs are modified to generate novel or labile morphologies. This requires an understanding of the molecular genetic basis of these programs and of the evolutionary changes they have undergone. The past decade has seen the establishment of a common language and common standards, and these changes have greatly improved the integration of evo-devo. Recently, a more comparative approach has been added to mechanistic developmental biology. In this review we attempt to show how, by using this “next-generation evo-devo” approach, insights into both developmental biology and evolutionary biology can be gained. Although the concepts we discuss are more broadly applicable, we have focused our examples on traits of the angiosperm flower, a structure that has undergone enormous morphological and developmental evolution since its relatively recent appearance in the fossil record.Work in the Glover laboratory on these topics is funded by the BBSRC, EU Marie Curie Actions, Isaac Newton Trust, Leverhulme Trust, NERC and the NSF, and we gratefully acknowledge all support.This is the accepted manuscript of a paper published in the International Journal of Plant Sciences (Glover BJ, Airoldi CA, Brockington SF, Fernández-Mazuecos M, Martínez-Pérez C, Mellers G, Moyroud E, Taylor L, International Journal of Plant Sciences, 2015, 176, 4, 307-323, doi:10.1086/681562). The final version is available at http://dx.doi.org/10.1086/68156

Fluid-Structural Coupling Effects on the Dynamics of Mistuned Bladed Disks

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77177/1/AIAA-23809-593.pd

Structural colour from helicoidal cell-wall architecture in fruits of Margaritaria nobilis

The bright and intense blue-green coloration of the fruits of Margaritaria nobilis (Phyllanthaceae) was investigated using polarization-resolved spectroscopy and transmission electron microscopy. Optical measurements of freshly collected fruits revealed a strong circularly polarized reflection of the fruit that originates from a cellulose helicoidal cell wall structure in the pericarp cells. Hyperspectral microscopy was used to capture the iridescent effect at the single-cell level.This work was supported by the Leverhulme Trust (F/09- 741/G) and a BBSRC David Phillips fellowship (BB/K014617/1). P.V. acknowledges support from the US Air Force Office of Scientific Research under award number FA9550-10-1-0020. U.S. acknowledges support from the Adolphe Merkle foundation and the Swiss National Science Foundation through the National Centre of Competence in Research Bio-Inspired Materials

A link between LEAFY and B-gene homologues in Welwitschia mirabilis sheds light on ancestral mechanisms prefiguring floral development

- Flowering plants evolved from an unidentified gymnosperm ancestor. Comparison of the mechanisms controlling development in angiosperm flowers and gymnosperm cones may help to elucidate the mysterious origin of the flower. - We combined gene expression studies with protein behaviour characterization in Welwitschia mirabilis to test whether the known regulatory links between LEAFY and its MADS-box gene targets, central to flower development, might also contribute to gymnosperm reproductive development. - We found that WelLFY, one of two LEAFY-like genes in Welwitschia, could be an upstream regulator of the MADS-box genes APETALA3/PISTILLATA-like (B-genes). We demonstrated that, even though their DNA-binding domains are extremely similar, WelLFY and its paralogue WelNDLY exhibit distinct DNA-binding specificities, and that, unlike WelNDLY, WelLFY shares with its angiosperm orthologue the capacity to bind promoters of Welwitschia B-genes. Finally, we identified several cis-elements mediating these interactions in Welwitschia and obtained evidence that the link between LFY homologues and B-genes is also conserved in two other gymnosperms, Pinus and Picea. - Although functional approaches to investigate cone development in gymnosperms are limited, our state-of-the-art biophysical techniques, coupled with expression studies, provide evidence that crucial links, central to the control of floral development, may already have existed before the appearance of flowers.This work was supported by funding from the Centre National de la Recherche Scientifique (ATIP+ to F.P.), the ANAgence Nationale de la Recherche (ANR) (Plant-TFcode to F.P. and C.P.S.), PhD fellowships from the University J. Fourier, Grenoble (to E.M. and M.M.), Grenoble Alliance for Cell and Structural Biology (ANR-10-LABX-49-01), the SYNTHESYS Project (to E.M.), the Floral Genome Project (National Science Foundation (NSF) Plant Genome Research Program project DBI-0115684 to M.W.F.) and NSF DEB-9974374 (to M.W.F.)

Reverse Engineering the Yeast RNR1 Transcriptional Control System

Transcription is controlled by multi-protein complexes binding to short non-coding regions of genomic DNA. These complexes interact combinatorially. A major goal of modern biology is to provide simple models that predict this complex behavior. The yeast gene RNR1 is transcribed periodically during the cell cycle. Here, we present a pilot study to demonstrate a new method of deciphering the logic behind transcriptional regulation. We took regular samples from cell cycle synchronized cultures of Saccharomyces cerevisiae and extracted nuclear protein. We tested these samples to measure the amount of protein that bound to seven different 16 base pair sequences of DNA that have been previously identified as protein binding locations in the promoter of the RNR1 gene. These tests were performed using surface plasmon resonance. We found that the surface plasmon resonance signals showed significant variation throughout the cell cycle. We correlated the protein binding data with previously published mRNA expression data and interpreted this to show that transcription requires protein bound to a particular site and either five different sites or one additional sites. We conclude that this demonstrates the feasibility of this approach to decipher the combinatorial logic of transcription

Role of transcriptional regulation in the evolution of plant phenotype: A dynamic systems approach

© 2015 Wiley Periodicals, Inc. A growing body of evidence suggests that alterations in transcriptional regulation of genes involved in modulating development are an important part of phenotypic evolution, and this can be documented among species and within populations. While the effects of differential transcriptional regulation in organismal development have been preferentially studied in animal systems, this phenomenon has also been addressed in plants. In this review, we summarize evidence for cis-regulatory mutations, trans-regulatory changes and epigenetic modifications as molecular events underlying important phenotypic alterations, and thus shaping the evolution of plant development. We postulate that a mechanistic understanding of why such molecular alterations have a key role in development, morphology and evolution will have to rely on dynamic models of complex regulatory networks that consider the concerted action of genetic and nongenetic components, and that also incorporate the restrictions underlying the genotype to phenotype mapping process.CONACyT 180098, 180380, 167705, 152649 and PAPIIT UNAM IN203214-3, IN203113-3, IN203814-3. BFU2012–34821 (MINECO) to C.G. and an institutional grant from Fundación Ramón Aceres to CBMSOPeer Reviewe

Two euAGAMOUS genes control C-function in Medicago truncatula

[EN] C-function MADS-box transcription factors belong to the AGAMOUS (AG) lineage and specify both stamen and carpel identity and floral meristem determinacy. In core eudicots, the AG lineage is further divided into two branches, the euAG and PLE lineages. Functional analyses across flowering plants strongly support the idea that duplicated AG lineage genes have different degrees of subfunctionalization of the C-function. The legume Medicago truncatula contains three C-lineage genes in its genome: two euAG genes (MtAGa and MtAGb) and one PLENA-like gene (MtSHP). This species is therefore a good experimental system to study the effects of gene duplication within the AG subfamily. We have studied the respective functions of each euAG genes in M. truncatula employing expression analyses and reverse genetic approaches. Our results show that the M. truncatula euAG- and PLENA-like genes are an example of subfunctionalization as a result of a change in expression pattern. MtAGa and MtAGb are the only genes showing a full C-function activity, concomitant with their ancestral expression profile, early in the floral meristem, and in the third and fourth floral whorls during floral development. In contrast, MtSHP expression appears late during floral development suggesting it does not contribute significantly to the C-function. Furthermore, the redundant MtAGa and MtAGb paralogs have been retained which provides the overall dosage required to specify the C-function in M. truncatula.This work was funded by grants BIO2009-08134 and BIO2012-39849-C02-01 from the Spanish Ministry of Economy and Competitiveness and the Ramon y Cajal Program (RYC-2007-00627 to CGM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Serwatowska, J.; Roque Mesa, EM.; Gómez Mena, MC.; Constantin, GD.; Wen, J.; Mysore, KS.; Lund, OS.... (2014). Two euAGAMOUS genes control C-function in Medicago truncatula. PLoS ONE. 9(8):103770-1-103770-12. https://doi.org/10.1371/journal.pone.0103770S103770-1103770-1298Prunet, N., & Jack, T. P. (2013). Flower Development in Arabidopsis: There Is More to It Than Learning Your ABCs. Flower Development, 3-33. doi:10.1007/978-1-4614-9408-9_1Causier, B., Schwarz-Sommer, Z., & Davies, B. (2010). Floral organ identity: 20 years of ABCs. Seminars in Cell & Developmental Biology, 21(1), 73-79. doi:10.1016/j.semcdb.2009.10.005Irish, V. F. (2010). The flowering of Arabidopsis flower development. The Plant Journal, 61(6), 1014-1028. doi:10.1111/j.1365-313x.2009.04065.xHeijmans, K., Morel, P., & Vandenbussche, M. (2012). MADS-box Genes and Floral Development: the Dark Side. Journal of Experimental Botany, 63(15), 5397-5404. doi:10.1093/jxb/ers233Bowman, J. L., Smyth, D. R., & Meyerowitz, E. M. (1989). Genes directing flower development in Arabidopsis. The Plant Cell, 1(1), 37-52. doi:10.1105/tpc.1.1.37Yanofsky, M. F., Ma, H., Bowman, J. L., Drews, G. N., Feldmann, K. A., & Meyerowitz, E. M. (1990). The protein encoded by the Arabidopsis homeotic gene agamous resembles transcription factors. Nature, 346(6279), 35-39. doi:10.1038/346035a0Bradley, D., Carpenter, R., Sommer, H., Hartley, N., & Coen, E. (1993). Complementary floral homeotic phenotypes result from opposite orientations of a transposon at the plena locus of antirrhinum. Cell, 72(1), 85-95. doi:10.1016/0092-8674(93)90052-rPinyopich, A., Ditta, G. S., Savidge, B., Liljegren, S. J., Baumann, E., Wisman, E., & Yanofsky, M. F. (2003). Assessing the redundancy of MADS-box genes during carpel and ovule development. Nature, 424(6944), 85-88. doi:10.1038/nature01741Liljegren, S. J., Ditta, G. S., Eshed, Y., Savidge, B., Bowman, J. L., & Yanofsky, M. F. (2000). SHATTERPROOF MADS-box genes control seed dispersal in Arabidopsis. Nature, 404(6779), 766-770. doi:10.1038/35008089Davies, B., Motte, P., Keck, E., Saedler, H., Sommer, H., & Schwarz-Sommer, Z. (1999). PLENA and FARINELLI: redundancy and regulatory interactions between two Antirrhinum MADS-box factors controlling flower development. The EMBO Journal, 18(14), 4023-4034. doi:10.1093/emboj/18.14.4023Kramer, E. M., Jaramillo, M. A., & Di Stilio, V. S. (2004). Patterns of Gene Duplication and Functional Evolution During the Diversification of the AGAMOUS Subfamily of MADS Box Genes in Angiosperms. Genetics, 166(2), 1011-1023. doi:10.1534/genetics.166.2.1011Becker, A. (2003). The major clades of MADS-box genes and their role in the development and evolution of flowering plants. Molecular Phylogenetics and Evolution, 29(3), 464-489. doi:10.1016/s1055-7903(03)00207-0Irish, V. F. (2003). The evolution of floral homeotic gene function. BioEssays, 25(7), 637-646. doi:10.1002/bies.10292Zahn, L. M., Leebens-Mack, J. H., Arrington, J. M., Hu, Y., Landherr, L. L., dePamphilis, C. W., … Ma, H. (2006). Conservation and divergence in the AGAMOUS subfamily of MADS-box genes: evidence of independent sub- and neofunctionalization events. Evolution Development, 8(1), 30-45. doi:10.1111/j.1525-142x.2006.05073.xFerrandiz, C. (2000). Negative Regulation of the SHATTERPROOF Genes by FRUITFULL During Arabidopsis Fruit Development. Science, 289(5478), 436-438. doi:10.1126/science.289.5478.436Ma, H., Yanofsky, M. F., & Meyerowitz, E. M. (1991). AGL1-AGL6, an Arabidopsis gene family with similarity to floral homeotic and transcription factor genes. Genes & Development, 5(3), 484-495. doi:10.1101/gad.5.3.484Savidge, B., Rounsley, S. D., & Yanofsky, M. F. (1995). Temporal relationship between the transcription of two Arabidopsis MADS box genes and the floral organ identity genes. The Plant Cell, 7(6), 721-733. doi:10.1105/tpc.7.6.721Colombo, M., Brambilla, V., Marcheselli, R., Caporali, E., Kater, M. M., & Colombo, L. (2010). A new role for the SHATTERPROOF genes during Arabidopsis gynoecium development. Developmental Biology, 337(2), 294-302. doi:10.1016/j.ydbio.2009.10.043Fourquin, C., & Ferrándiz, C. (2012). Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots. The Plant Journal, 71(6), 990-1001. doi:10.1111/j.1365-313x.2012.05046.xKapoor, M., Tsuda, S., Tanaka, Y., Mayama, T., Okuyama, Y., Tsuchimoto, S., & Takatsuji, H. (2002). Role of petuniapMADS3in determination of floral organ and meristem identity, as revealed by its loss of function. The Plant Journal, 32(1), 115-127. doi:10.1046/j.1365-313x.2002.01402.xPan, I. L., McQuinn, R., Giovannoni, J. J., & Irish, V. F. (2010). Functional diversification of AGAMOUS lineage genes in regulating tomato flower and fruit development. Journal of Experimental Botany, 61(6), 1795-1806. doi:10.1093/jxb/erq046Pnueli, L., Hareven, D., Rounsley, S. D., Yanofsky, M. F., & Lifschitz, E. (1994). Isolation of the tomato AGAMOUS gene TAG1 and analysis of its homeotic role in transgenic plants. The Plant Cell, 6(2), 163-173. doi:10.1105/tpc.6.2.163Dreni, L., & Kater, M. M. (2013). MADSreloaded: evolution of theAGAMOUSsubfamily genes. New Phytologist, 201(3), 717-732. doi:10.1111/nph.12555Brunner, A. M. (2000). Plant Molecular Biology, 44(5), 619-634. doi:10.1023/a:1026550205851Perl-Treves, R., Kahana, A., Rosenman, N., Xiang, Y., & Silberstein, L. (1998). Expression of Multiple AGAMOUS-Like Genes in Male and Female Flowers of Cucumber (Cucumis sativus L.). Plant and Cell Physiology, 39(7), 701-710. doi:10.1093/oxfordjournals.pcp.a029424Yu, D., Kotilainen, M., Pöllänen, E., Mehto, M., Elomaa, P., Helariutta, Y., … Teeri, T. H. (1999). Organ identity genes and modified patterns of flower development in Gerbera hybrida (Asteraceae). The Plant Journal, 17(1), 51-62. doi:10.1046/j.1365-313x.1999.00351.xDong, Z., Zhao, Z., Liu, C., Luo, J., Yang, J., Huang, W., … Luo, D. (2005). Floral Patterning in Lotus japonicus. Plant Physiology, 137(4), 1272-1282. doi:10.1104/pp.104.054288Hofer, J. M., & Noel Ellis, T. (2014). Developmental specialisations in the legume family. Current Opinion in Plant Biology, 17, 153-158. doi:10.1016/j.pbi.2013.11.014Fourquin, C., del Cerro, C., Victoria, F. C., Vialette-Guiraud, A., de Oliveira, A. C., & Ferrándiz, C. (2013). A Change in SHATTERPROOF Protein Lies at the Origin of a Fruit Morphological Novelty and a New Strategy for Seed Dispersal in Medicago Genus. Plant Physiology, 162(2), 907-917. doi:10.1104/pp.113.217570Hewitt EJ (1966) Sand and Water Culture Methods Used in the Study of Plant Nutrition. Farnham Royal, UK: Commonwealth Agricultural Bureau.Cheng, X., Wang, M., Lee, H.-K., Tadege, M., Ratet, P., Udvardi, M., … Wen, J. (2013). An efficient reverse genetics platform in the model legumeMedicago truncatula. New Phytologist, 201(3), 1065-1076. doi:10.1111/nph.12575D’ Erfurth, I., Cosson, V., Eschstruth, A., Lucas, H., Kondorosi, A., & Ratet, P. (2003). Efficient transposition of theTnt1tobacco retrotransposon in the model legumeMedicago truncatula. The Plant Journal, 34(1), 95-106. doi:10.1046/j.1365-313x.2003.01701.xTadege, M., Ratet, P., & Mysore, K. S. (2005). Insertional mutagenesis: a Swiss Army knife for functional genomics of Medicago truncatula. Trends in Plant Science, 10(5), 229-235. doi:10.1016/j.tplants.2005.03.009Tadege, M., Wen, J., He, J., Tu, H., Kwak, Y., Eschstruth, A., … Mysore, K. S. (2008). Large-scale insertional mutagenesis using the Tnt1 retrotransposon in the model legume Medicago truncatula. The Plant Journal, 54(2), 335-347. doi:10.1111/j.1365-313x.2008.03418.xCheng, X., Wen, J., Tadege, M., Ratet, P., & Mysore, K. S. (2010). Reverse Genetics in Medicago truncatula Using Tnt1 Insertion Mutants. Plant Reverse Genetics, 179-190. doi:10.1007/978-1-60761-682-5_13Benlloch, R., d’ Erfurth, I., Ferrandiz, C., Cosson, V., Beltrán, J. P., Cañas, L. A., … Ratet, P. (2006). Isolation of mtpim Proves Tnt1 a Useful Reverse Genetics Tool in Medicago truncatula and Uncovers New Aspects of AP1-Like Functions in Legumes. Plant Physiology, 142(3), 972-983. doi:10.1104/pp.106.083543Larkin, M. A., Blackshields, G., Brown, N. P., Chenna, R., McGettigan, P. A., McWilliam, H., … Higgins, D. G. (2007). Clustal W and Clustal X version 2.0. Bioinformatics, 23(21), 2947-2948. doi:10.1093/bioinformatics/btm404Altschul, S. (1997). Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Research, 25(17), 3389-3402. doi:10.1093/nar/25.17.3389Tamura, K., Dudley, J., Nei, M., & Kumar, S. (2007). MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) Software Version 4.0. Molecular Biology and Evolution, 24(8), 1596-1599. doi:10.1093/molbev/msm092Dellaporta, S. L., Wood, J., & Hicks, J. B. (1983). A plant DNA minipreparation: Version II. Plant Molecular Biology Reporter, 1(4), 19-21. doi:10.1007/bf02712670Schmittgen, T. D., & Livak, K. J. (2008). Analyzing real-time PCR data by the comparative CT method. Nature Protocols, 3(6), 1101-1108. doi:10.1038/nprot.2008.73Constantin, G. D., Krath, B. N., MacFarlane, S. A., Nicolaisen, M., Elisabeth Johansen, I., & Lund, O. S. (2004). Virus-induced gene silencing as a tool for functional genomics in a legume species. The Plant Journal, 40(4), 622-631. doi:10.1111/j.1365-313x.2004.02233.xWesley, S. V., Helliwell, C. A., Smith, N. A., Wang, M., Rouse, D. T., Liu, Q., … Waterhouse, P. M. (2001). Construct design for efficient, effective and high-throughput gene silencing in plants. The Plant Journal, 27(6), 581-590. doi:10.1046/j.1365-313x.2001.01105.xGuerineau F, Mullineaux P (1993) Plant transformation and expression vectors. In: Croy R, editor. Plant Molecular Biology. Oxford, UK: Bios Scientific Publishers, Academic Press. pp. 121–147.Clough, S. J., & Bent, A. F. (1998). Floral dip: a simplified method forAgrobacterium-mediated transformation ofArabidopsis thaliana. The Plant Journal, 16(6), 735-743. doi:10.1046/j.1365-313x.1998.00343.xBenlloch, R., Roque, E., Ferrándiz, C., Cosson, V., Caballero, T., Penmetsa, R. V., … Madueño, F. (2009). Analysis of B function in legumes: PISTILLATA proteins do not require the PI motif for floral organ development inMedicago truncatula. The Plant Journal, 60(1), 102-111. doi:10.1111/j.1365-313x.2009.03939.xRoque, E., Serwatowska, J., Cruz Rochina, M., Wen, J., Mysore, K. S., Yenush, L., … Cañas, L. A. (2012). Functional specialization of duplicated AP3-like genes inMedicago truncatula. The Plant Journal, 73(4), 663-675. doi:10.1111/tpj.12068Flanagan, C. A., Hu, Y., & Ma, H. (1996). Specific expression of the AGL1 MADS-box gene suggests regulatory functions in Arabidopsis gynoecium and ovule development. The Plant Journal, 10(2), 343-353. doi:10.1046/j.1365-313x.1996.10020343.xSieburth, L. E., & Meyerowitz, E. M. (1997). Molecular dissection of the AGAMOUS control region shows that cis elements for spatial regulation are located intragenically. The Plant Cell, 9(3), 355-365. doi:10.1105/tpc.9.3.355Busch, M. A. (1999). Activation of a Floral Homeotic Gene in Arabidopsis. Science, 285(5427), 585-587. doi:10.1126/science.285.5427.585Moyroud, E., Minguet, E. G., Ott, F., Yant, L., Posé, D., Monniaux, M., … Parcy, F. (2011). Prediction of Regulatory Interactions from Genome Sequences Using a Biophysical Model for the Arabidopsis LEAFY Transcription Factor. The Plant Cell, 23(4), 1293-1306. doi:10.1105/tpc.111.083329Grønlund, M., Constantin, G., Piednoir, E., Kovacev, J., Johansen, I. E., & Lund, O. S. (2008). Virus-induced gene silencing in Medicago truncatula and Lathyrus odorata. Virus Research, 135(2), 345-349. doi:10.1016/j.virusres.2008.04.005Mandel, M. A., Bowman, J. L., Kempin, S. A., Ma, H., Meyerowitz, E. M., & Yanofsky, M. F. (1992). Manipulation of flower structure in transgenic tobacco. Cell, 71(1), 133-143. doi:10.1016/0092-8674(92)90272-eMizukami, Y., & Ma, H. (1992). Ectopic expression of the floral homeotic gene AGAMOUS in transgenic Arabidopsis plants alters floral organ identity. Cell, 71(1), 119-131. doi:10.1016/0092-8674(92)90271-dCannon, S. B., Sterck, L., Rombauts, S., Sato, S., Cheung, F., Gouzy, J., … Young, N. D. (2006). Legume genome evolution viewed through the Medicago truncatula and Lotus japonicus genomes. Proceedings of the National Academy of Sciences, 103(40), 14959-14964. doi:10.1073/pnas.0603228103Young, N. D., & Bharti, A. K. (2012). Genome-Enabled Insights into Legume Biology. Annual Review of Plant Biology, 63(1), 283-305. doi:10.1146/annurev-arplant-042110-103754Jager, M. (2003). MADS-Box Genes in Ginkgo biloba and the Evolution of the AGAMOUS Family. Molecular Biology and Evolution, 20(5), 842-854. doi:10.1093/molbev/msg089Johansen, B., Pedersen, L. B., Skipper, M., & Frederiksen, S. (2002). MADS-box gene evolution—structure and transcription patterns. Molecular Phylogenetics and Evolution, 23(3), 458-480. doi:10.1016/s1055-7903(02)00032-5Rutledge, R., Regan, S., Nicolas, O., Fobert, P., Côté, C., Bosnich, W., … Stewart, D. (1998). Characterization of an AGAMOUS homologue from the conifer black spruce ( Picea mariana ) that produces floral homeotic conversions when expressed in Arabidopsis. The Plant Journal, 15(5), 625-634. doi:10.1046/j.1365-313x.1998.00250.xParcy, F., Nilsson, O., Busch, M. A., Lee, I., & Weigel, D. (1998). A genetic framework for floral patterning. Nature, 395(6702), 561-566. doi:10.1038/26903Causier, B., Bradley, D., Cook, H., & Davies, B. (2009). Conserved intragenic elements were critical for the evolution of the floral C-function. The Plant Journal, 58(1), 41-52. doi:10.1111/j.1365-313x.2008.03759.xAiroldi, C. A., & Davies, B. (2012). Gene Duplication and the Evolution of Plant MADS-box Transcription Factors. Journal of Genetics and Genomics, 39(4), 157-165. doi:10.1016/j.jgg.2012.02.008Giménez, E., Pineda, B., Capel, J., Antón, M. T., Atarés, A., Pérez-Martín, F., … Lozano, R. (2010). Functional Analysis of the Arlequin Mutant Corroborates the Essential Role of the ARLEQUIN/TAGL1 Gene during Reproductive Development of Tomato. PLoS ONE, 5(12), e14427. doi:10.1371/journal.pone.0014427Kater, M. M., Colombo, L., Franken, J., Busscher, M., Masiero, S., Van Lookeren Campagne, M. M., & Angenent, G. C. (1998). Multiple AGAMOUS Homologs from Cucumber and Petunia Differ in Their Ability to Induce Reproductive Organ Fate. The Plant Cell, 10(2), 171-182. doi:10.1105/tpc.10.2.171Tsuchimoto, S., van der Krol, A. R., & Chua, N. H. (1993). Ectopic expression of pMADS3 in transgenic petunia phenocopies the petunia blind mutant. The Plant Cell, 5(8), 843-853. doi:10.1105/tpc.5.8.843Airoldi, C. A., Bergonzi, S., & Davies, B. (2010). Single amino acid change alters the ability to specify male or female organ identity. Proceedings of the National Academy of Sciences, 107(44), 18898-18902. doi:10.1073/pnas.1009050107Causier, B., Castillo, R., Zhou, J., Ingram, R., Xue, Y., Schwarz-Sommer, Z., & Davies, B. (2005). Evolution in Action: Following Function in Duplicated Floral Homeotic Genes. Current Biology, 15(16), 1508-1512. doi:10.1016/j.cub.2005.07.063Birchler, J. A., & Veitia, R. A. (2007). The Gene Balance Hypothesis: From Classical Genetics to Modern Genomics. The Plant Cell, 19(2), 395-402. doi:10.1105/tpc.106.049338Birchler, J. A., & Veitia, R. A. (2009). The gene balance hypothesis: implications for gene regulation, quantitative traits and evolution. New Phytologist, 186(1), 54-62. doi:10.1111/j.1469-8137.2009.03087.xEdger, P. P., & Pires, J. C. (2009). Gene and genome duplications: the impact of dosage-sensitivity on the fate of nuclear genes. Chromosome Research, 17(5), 699-717. doi:10.1007/s10577-009-9055-9Freeling, M. (2006). Gene-balanced duplications, like tetraploidy, provide predictable drive to increase morphological complexity. Genome Research, 16(7), 805-814. doi:10.1101/gr.368140

Analysing photonic structures in plants

The outer layers of a range of plant tissues, including flower petals, leaves and fruits, exhibit an intriguing variation of microscopic structures. Some of these structures include ordered periodic multilayers and diffraction gratings that give rise to interesting optical appearances. The colour arising from such structures is generally brighter than pigment-based colour. Here, we describe the main types of photonic structures found in plants and discuss the experimental approaches that can be used to analyse them. These experimental approaches allow identification of the physical mechanisms producing structural colours with a high degree of confidence. © 2013 The Author(s) Published by the Royal Society. All rights reserved